On a recent trip I had a warning light come on and observed the oil pressure on my O320-D1A engine declining to about 30 psi. After about 30 butt clenching seconds it went back to around 80 psi my normal range. I have flown the plane now another hour or so with no abnormal indication. An oil change, filter cut and screen inspection showed nothing amiss. The oil change had 52 hours on it so there was a good sampling of any debris in the system. I’m not about to stick my head in the clouds until I get this figured out. This engine has been dead on reliable for over 900 hours and now this. Hopefully someone in VAF land can give me some reliable information to assist in determining the cause of the issue.